Is the legal killing of lynx and wolverines selective?

Published 9 Sep 2010

A new report from the Scandinavian research project on lynx (Scandlynx) and the Swedish wolverine project (Järvprosjektet) considers the effect of legal killing of predators as a means of reducing damage to sheep and reindeer. The report bases its analysis on behavioral studies of GPS-marked lynx and wolverine.

The most common way of reducing damage towards sheep and semi-domestic reindeer in Norway today are actions taken against the predator, in accordance with legislation that gives permission to kill predatory wildlife causing damage. Quota-hunting and licensed hunting regulate predator populations on a large scale and thus reduces the damage to sheep and reindeer. The effect of removing certain “problem individuals” is firstly dependent on there actually being individuals that cause more damage than others in a predator population. In principle there may be certain problem individuals that perform more damage than others within a continuous population of predators. Another option is to define a problem individual as one that has access to sheep, for instance a wolf outside the wolf zone. Secondly an efficient removal of problem individuals presupposes that the removal is selective, i.e. that it is the actual individual doing a lot of damage that is removed.

Commissioned by the Norwegian Directorate for Nature Management we have analysed an extensive collection of data on the behavior of radio- or GPS-marked lynx and wolverine in connection with predation on sheep and semi-domesticated reindeer in Scandinavia. On average, female lynx with kittens visited a reindeer or sheep carcass over a period of three days, while male lynx used half the time. In contrast to lynx, wolverines would often divide up and cache large prey such as reindeer. It may therefore be several days or weeks between each time wolverines visit a carcass. In only half of the incidences wolverines came back to a killed reindeer the next day, and they returned to the carcass from 1 to 26 days in the course of the following month. Only on rare occasions reindeer carcasses were visited by more than one lynx. However, more than a third of the reindeer killed by a wolverine were also visited by several other wolverines. Already on the first day, 17% of all carcasses were visited by more than one wolverine. In a situation where a wolverine is legally removed, there is always a risk that this is another wolverine than the one that actually killed the prey, even if the wolverine is shot within 24 hours after the damage has been made.

Removing problem individuals at or close to the killed sheep or reindeer can be efficient, selective and ethically justifiable outside areas where reproducing populations of predators are found, as long as the predator is removed quickly (within 48 hours) after the sheep or reindeer has been killed. In these areas the chance of shooting a female lynx with offspring, or another wolverine than the one that actually caused the damage, is minimal. The chance that the removal causes a local reduction in the loss of sheep and reindeer will also be relatively large. In areas (management zones) with populations of reproducing lynx, however, the risk of removing female lynx with dependent offspring will be high. Likewise, in areas with reproducing wolverine populations, the removal would be rather unselective. For both species, the effect of removing individuals in areas with reproducing populations would not last for long.